Русский   English
WMMT

News

Wire EDMs offer increase of 40% in feed rates

11.07.2004

With the launch of pulse control, feed rates can be increased by up to 40 per cent on the latest EDMs, which are claimed to have the fastest disconnection to reconnection automatic wire feed.

With the launch of A1 pulse control, feed rates can be increased by up to 40 per cent on the latest Fanuc Robocut Alpha-iC series of wire electro-discharge machines.

And, when combined with the latest Nano Interpolation development giving NC commands to the machine servodrives with an ultra-fine pitch of 0.001mm, high speed cutting up to 330mm2/min using 0.3mm brass wire can be performed with a high precision capability such as holding roundness to within 1.2 microns on a 30mm diameter hole to a surface finish of 0.7 microns.

The two new robocut machines in the C-Series from 600 Centre of Shepshed, Loughborough, are available in the 0 version, having cutting strokes of 320 mm by 220mm by 180mm and a 500kg table loading or the larger capacity I variant, having cutting strokes of 550mm by 370mm by 310mm and a one tonne table loading.

Both machines feature the latest Fanuc 180 is - WB advanced control.

This system also supports the claims of the world's fastest disconnection to reconnection automatic wire feed (AWF) in just 12 secs using thermal melting techniques.

The class-leading developments of the patent pending AI pulse control enables precise monitoring of the number of pulses applied to the cutting process and responsive issue by the CNC control of velocity commands.

This reaction enables the energy density and discharge gap between wire and workpiece to be optimised and kept uniform throughout the cutting process.

As a result problems such as wire breakage due to concentrated discharge are eliminated and with the increased smoothness of axis motions, accommodates initial penetration into the workpiece by the wire and overcomes any variation at the point of cut.

This enables feed rates to be improved by up to 40 per cent over conventional Fanuc wire machines with less likelihood of wire breakage.

As Nano Interpolation software distributes positioning commands from the CNC control with a pitch of 0.001mm (one nanometre) to the axis servo motors, which are equipped with ultra-high resolution 16 million pulse coder feeds, any accumulation of axial movement errors are eliminated giving a very precise and smoother feed to further enhance the machining accuracy.

When these new developments are combined with well-proven functions such as high speed non-electrolysis AC cutting and the latest AI active corner control, that pre-empts a change in either the roughing or finishing cutting path and removes any slack from the wire feed, precise corner control can be achieved without having to modify the programmed cutting path.

A micro finish power supply option also enables fine surface finishes as high as 0.7 microns to be achieved.

The ultra-high speed AWF system thermally melts the wire which dramatically simplifies the wire cutting mechanism design reducing service demands and extending the reliability of the machine.

The annealing effect of the heat generated in the wire improves its straightness and creates a very sharp edge at the point of cut.

With the thermal melting system, wire disconnection takes just four seconds and wire reconnection eight seconds, while the sharp edge created helps automatic insertion of the wire in the wire guide and eliminates any need for a split guide.

As an option, this system can be applied to finer wire diameters between 0.05mm and 0.07mm.

Wire threading can also be performed while submerged on workpieces up to 100 mm thick which eliminates time to drain and refill the tank and hence improves the productivity of the process.

As a further addition, to help in applications involving unmanned wire cutting, when the process start hole is very small or the hole is not in the correct position, the control system software will automatically search for a position where connection can be made.

And, if a short-circuit occurs after connection, it will automatically carry out a search for a short-circuit released position.

Should the automatic re-connection of wire be required, it can be performed on, or very close to the breakage point in the profiled cutting groove without having to return to the start position.

The Fanuc Alpha-OiC has a maximum workpiece capacity of 650mm by 450mm by 180mm with table travel of 320mm by 220mm while the Alpha-IiC will accommodate parts up to 830mm by 730mm by 300mm as standard.

As an option, this can be increased to 1000mm by 730mm by 300mm.

Table travel is 550mm by 370mm.

The U and V axis travels on both machines is +/-60mm by +/-60mm and maximum standard taper angle is +/- 30deg over 80mm.

As an option, this can be increased to +/-45deg over 40mm.

Wire size as standard is 0.1mm to 0.3mm with option of 0.05 mm to 0.3 mm diameter.

Maximum wire capacity is 16kg however, an optional 20kg supply can be provided.

Search
 

 

Partners